This was in 1906 and the cost of living has advanced considerably since then. Dr. Ryan would probably, therefore, not consider too high the estimate of the Bureau of Labor (l. c.) of $600.00 for cotton mill operatives in the South. Under this standard, the father supports the family, the mother stays at home looking after the house, and the children go to school. It includes insurance. Now for the sake of argument let us assume that laborers have a strict right in justice to a standard represented by $600.00 a year in a Southern mill town. I must reluctantly admit that $600.00 cannot be proved conclusively to be the sum to which all laborers have a right. But for the time being we shall take it for granted, and from the standpoint of this assumption judge the justice or injustice of industrial conditions. I have said that I do not think that this obligation can be _proved conclusively_, that is, as conclusively as a proposition in geometry. But I do think that it is capable of the same proof that we have for many other moral truths that pass unquestioned. We must beware of applying to new propositions that corrosive logic which, if impartially exercised on old and new alike, would destroy the very basis of morality. This principle, that moral truths cannot be absolutely demonstrated, is generally admitted and many concrete examples could be given from prominent ethicists: thus De Lugo in speaking of so fundamental a question as the unlawfulness of suicide, does not hesitate to say: "The whole difficulty consists in assigning a reason for this truth: for though its [suicide's] turpitude is immediately apparent, it is not easy to find the foundation of this judgment: whence (_a thing that happens in many other questions_) the conclusion is more certain than the reason adduced by various authors for its proof."[34] Again, Ballerini, in treating of the unlawfulness of one of the sins mentioned by St. Paul in the sixth chapter of his first Epistle to the Corinthians, remarks that "it is most difficult to assign a reason for this." Then, after rejecting all the reasons usually brought forward, he adds: "It must be admitted that there are some practical truths necessary for the right association of men with each other, which men feel and perceive by a sort of rational instinct, whose reason, nevertheless (at least a demonstrative one), when these same men seek it analytically, they find it hard to discover. It would seem that nature, or the Author of our nature, wished to supply the defect of the exercise of reason by an instinct or rational sense of this kind: ... Among the truths of this nature, the one of which we treat happens to be found."[35]